create sent/junk/trash folders for IMAP?

i followed the how-to guide for ISPConfig for Ubuntu 7.04, and used Courier for IMAP. When I create a new mail user, it does not create the sent, junk, or trash folders for the user, only the inbox. I realize the mailuser could create the folders in their mail client, but I guess the issue is that the mail wont' automatically be moved to the appropriate folder.

So I guess my question is two part:

1) How do i manually add the sent/junk/trash folders for my existing mail users?

and

2) What do I need to modify to the users created in the future have these folders by default.